[cc] Add and plumb CFS::DidNotProduceFrame.

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1921 matching lines @@
 
   impl_thread_phase_ = ImplThreadPhase::INSIDE_IMPL_FRAME;
 }
 
 void LayerTreeHostImpl::DidFinishImplFrame() {
   impl_thread_phase_ = ImplThreadPhase::IDLE;
   current_begin_frame_tracker_.Finish();
   decoded_image_tracker_.NotifyFrameFinished();
 }
 
+void LayerTreeHostImpl::BeginFrameDidNotProduceFrame(const BeginFrameAck& ack) {
+  compositor_frame_sink_->BeginFrameDidNotProduceFrame(ack);

[sunnyps, 2017/05/22 07:17:12]

nit: Check if compositor_frame_sink_ is non-null because the CFS can be lost.

[Eric Seckler, 2017/05/22 11:29:58]

Done.

+}
+
 void LayerTreeHostImpl::UpdateViewportContainerSizes() {
   LayerImpl* inner_container = active_tree_->InnerViewportContainerLayer();
   LayerImpl* outer_container = active_tree_->OuterViewportContainerLayer();
 
   if (!inner_container)
     return;
 
   ViewportAnchor anchor(InnerViewportScrollLayer(), OuterViewportScrollLayer());
 
   float top_controls_layout_height =
@@ skipping 2390 matching lines @@
 
 void LayerTreeHostImpl::ShowScrollbarsForImplScroll(ElementId element_id) {
   if (!element_id)
     return;
   if (ScrollbarAnimationController* animation_controller =
           ScrollbarAnimationControllerForElementId(element_id))
     animation_controller->DidScrollUpdate();
 }
 
 }  // namespace cc